The hardening and narrowing of the arteries called atherosclerosis is a common complication of diabetes. One marker of atherosclerosis is the thickness of the carotid arteries — the vessels that carry blood to the head, neck and brain.

Kristie K. Danielson, PhD, of the University of Illinois at Chicago, and colleagues found pancreatic islet transplantation reduced carotid artery thickness in patients with type 1 diabetes.

The decrease in carotid artery thickness was associated with a decrease in levels of HbA1c.

According to the study’s authors, these findings suggest islet transplantation may improve diabetes-related atherosclerosis by improving blood sugar control in patients with type 1 diabetes.

From their study of 15 patients with type 1 diabetes, Dr. Danielson and colleagues found carotid intima-media thickness decreased by about 0.058 mm 12 months after patients underwent islet transplantation. The decrease continued from 12 to 50 months after islet transplantation.

Even though the thickness of the carotid artery is associated with atherosclerosis, thickening of the artery is not necessarily caused by atherosclerosis. However, once the carotid artery reaches a certain thickness, patients may almost certainly have atherosclerosis.

This study did not show that islet transplantation prevented atherosclerosis. Furthermore, the study did not show that islet transplantation directly caused the decrease in carotid artery thickness. Still, patients who underwent islet transplantation had improved HbA1c and better control of diabetes, which is known to reduce the risk of diabetes-related complications, including cardiovascular problems like atherosclerosis.